Rihanna and Chris Brown partied in different cities over the holiday weekend, but both managed to raise eyebrows with the company they kept.

Let's start with Brown, who, despite his recent prison-avoiding guilty plea in the February assault on his Grammy-winning ex, apparently isn't lacking female company -- or invitations to high-profile Hollywood events.

The New York Daily News claims the singer, 20, who's currently sporting a red lightning bolt on the back of his head, puckered up with Kanye West's sometime squeeze, Amber Rose, during Diddy's annual Fourth of July White Party in Beverly Hills, Calif.

Brown, who is barred from contacting Rihanna as part of his plea deal, turned up at the bash with friend -- and RiRi style double -- Teyana Taylor and was soon spotted dancing to "Thriller" before starting to groove with the leggy, buzz cut-topped Rose.

After they were done hoofing, the pair supposedly cozied up on a backyard couch as the crowd thinned out.

"They were holding hands and making out in the shadows," a spywitness tells the paper. "She had her hand on his leg."

But the gorgeous chanteuse didn't appear to need any help as she celebrated Independence Day in Las Vegas with mentor Jay-Z, who reportedly banned Brown from taking part in the Michael Jackson tribute at the recent BET Awards.

On Saturday, Rihanna joined Jay at an MC Hammer and Vanilla Ice show at the Wet Republic pool, although she appeared to be more interested in hanging out with a new guy instead of checking out the rap-light song stylings of faded '80s stars.

The bikini-clad singer, who in recent weeks has been linked to Canadian rapper Aubrey "Drake" Graham (he insists they're just friends), was spied sitting on the mystery man's lap as he kept one arm around her waist (he also looked to be wearing a wedding ring, so perhaps this was nothing more than a warm gesture between friends).